title: Cognitive functioning and GABAA/benzodiazepine receptor binding in schizophrenia: a 123I-iomazenil SPET study.
abstract: BACKGROUND
  The role of the inhibitory neurotransmitter gamma aminobutyric acid (GABA) in schizophrenia has previously been investigated using postmortem material. Recently, using single photon emission tomography (SPET) with the selective benzodiazepine antagonist 123I-Iomazenil as the radioligand, we have demonstrated an in vivo relationship between reduced GABAA/benzodiazepine receptor binding and the severity of positive symptomatology in schizophrenia. The present study aimed to build on this using the same in vivo scanning techniques, and relating findings to cognitive functioning.
  
  
  METHODS
  Ten nonpsychiatric control subjects and 15 schizophrenic patients, matched for age and handedness, were scanned. A battery of neuropsychologic tests was also administered.
  
  
  RESULTS
  Correlational analysis revealed a pattern of increased correlations between GABAA/benzodiazepine receptor binding and task performance, in the schizophrenic group compared to the control group.
  
  
  CONCLUSIONS
  Findings are preliminary but suggest a relationship between reduced GABAA/benzodiazepine receptor binding and poorer cognitive functioning, involving memory and visual attention processes, in the schizophrenic group but not in the control group. A role for GABA in the pathophysiology of schizophrenia is suggested. Limitations of the present study and suggestions for future research are discussed.
authors.affiliation: Department of Psychology, University of London, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Ball
authors.forename: G F
authors.initials: GF
authors.lastname: Busatto
authors.forename: A S
authors.initials: AS
authors.lastname: David
authors.forename: S H
authors.initials: SH
authors.lastname: Jones
authors.forename: D R
authors.initials: DR
authors.lastname: Hemsley
authors.forename: L S
authors.initials: LS
authors.lastname: Pilowsky
authors.forename: D C
authors.initials: DC
authors.lastname: Costa
authors.forename: P J
authors.initials: PJ
authors.lastname: Ell
authors.forename: R W
authors.initials: RW
authors.lastname: Kerwin
mesh_terms: D000328:Adult; D003071:Cognition / Q000502:physiology*; D005260:Female; D005442:Flumazenil / Q000031:analogs & derivatives*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D011963:Receptors, GABA-A / Q000378:metabolism*; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000378:metabolism*; D012565:Schizophrenic Psychology; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D007457:Iodine Radioisotopes; D011963:Receptors, GABA-A; D005442:Flumazenil; C063038:iomazenil